Something needs to threaten your sense of how things should be while also seeming safe, acceptable, or okay.

Both babies and non-human primates laugh when chased, tickled, or attacked in a safe and friendly way. As any slapstick comedian knows, physical threats, like an assault with a banana cream pie, similarly elicits laughter in adults.

As humans evolved and developed culture, language, logic, and a sense of self, people could experience threat, and sometimes humorous reactions to a wider range of situations. Thus, humor transcends physical gags to include violations related to social norms (think fart jokes), logic (think absurdities), communication norms (think sarcasm), and identity (think insult roasts).

Of course, violations do not usually make people laugh. They make people angry, disgusted or confused. For a violation to be funny, it also needs to seem safe, acceptable, or okay.

Many things make a violation benign:

a playful state of mind

cues that a situation is okay

a reason why the situation is acceptable

feeling that a situation is far away

or, a low commitment to what is threatened

The theory also explains the two ways humor attempts can fail. Sometimes there is no violation. You can’t tickle yourself because there is not threat of attack. Other times, there is nothing benign. You are not likely to laugh when tickled by a creepy stranger.